Viruses

antigenic drift

When mutations accumulate in viral surface protein genes, causing changes in the virus's antigenic properties. This can make vaccines less effective and increase the risk of infection.

antigenic shift

A sudden change in the surface antigens of a virus, caused by the exchange of genetic material with another virus, resulting in a new strain that can evade the immune system.

Cytopathic

Refers to the ability of a virus to cause damage to the host cell it infects, leading to cell death or dysfunction.

genome

The complete set of genetic material that an organism possesses, including all of its genes and non-coding DNA sequences.